Spray your slow cooker with non-stick cooking spray.
Place pork in slow cooker. Pour root beer over the pork. Cover and cook on low heat for 6 to 8 hours or until it shreds easily with two forks.
Remove pork and shred it using two forks.
Drain most of the liquid from slow cooker (keep about 1/2 cup), and return shredded pork to slow cooker, stir in barbecue sauce. Continue heating on low for an additional 30 minutes, until warmed through.